Firing One-Handed

When a hero carries a handgun, he or she will tend to wield it and sometimes fire it in one hand. Perfect for still photo opportunities where the shooter's arm is bent above and behind their head and the gun is brought down to aim and fire. Even more cool is firing a gun sideways.

The exception is if they are military or police officers, where they will use two hands. Unless they've gone rogue and/or are desperate.

And sometimes the hero will have a gun in each hand. Or a sword in the other.

Justified in most westerns, as the single action triggers used at the time made it more popular to fire with one hand and fan the hammer with the other. Although films depicting one-handed use of revolvers will often not show the hammer being fanned at all.

There's also a school of thought that says aiming one-handed whilst standing sideways-on to your opponent presents a narrower target and thus makes you harder to hit; whether this makes up for your own increased difficulty in hitting anything is a matter for opinion.

And then there are cases when someone is using a longarm one-handed. These weapons were never even meant for one-handed use, but it happens for some reason. Submachine guns are popularly shown this way, as they often look good in one hand, but they are still intended for two-handed use. This is the only way rifles and such can be used Guns Akimbo, but doesn't exactly look realistic.

For really big melee weapons being used in one hand, see One-Handed Zweihander.

Has nothing to do with another one-handed activity.

Examples of Firing One-Handed include:

Handguns and Other Small Arms

MOD NOTE: Before adding a handgun (and handgun refers to pistols, revolvers, and pistol-styled SMG weapons), unless it is of a VERY high caliber where it would be illogical and/or dangerous to the shooter to fire one-handed, it does NOT need to be added here unless there are other circumstances making one-handed fire unusual. High caliber refers to calibers such as .50AE, .500 Smith and Wesson, and similar. If not sure, look it up first.

Anime and Manga

In the booklet of StrikerS Sound Stage X, all art of Magical Girl Lyrical Nanoha's Teana with the Cross Mirage's Blazer Mode show her wielding it one-handed. A little weird since she usually uses her gun with two hands when she's not going Guns Akimbo or using her other hand for something else.
Subverted in DOGS Bullets and Carnage. Mihai chastises Ian to "stop trying to look cool" and hold his gun in two hands when he sees him practicing with a one-handed grip.

Comic Books

Invoked and subverted in Queen and Country: Russian gangsters hired to kill Tara Chace fire their guns one-handed; most of their bullets hit nothing, and one unlucky goon catches a stray bullet from his ally.

Film

None of the many Desert Eagles in the Charlie's Angels movies is ever fired two-handed. And yes, this does require the Rule of Cool to keep those Hand Cannons from ripping people's wrists off like they would usually do in Real Life.
All the characters in The Matrix fire all manner of weapons one-handed, sometimes while performing various acrobatics, including one character who at one point dual-wields a pair of drum-fed automatic shotguns. This is all possible because it's happening in the Matrix, where the characters can bend the laws of physics.

Literature

The Dark Tower: Roland specifically lampshades this; real gunslingers are so awesome they don't need to use the other hand to steady themselves.
- Not to mention that they are old west-style revolvers, which were made for one-handed use.
- And, in the beginning of the second book, Roland loses several fingers from his right hand, which would make it difficult to use a two-handed grip.
- This goes so far, in that Roland uses a revolver per hand before above happens. It goes so far that he draws, shoots, (probably) cocks the gun, and even reloads with one hand per gun, one bullet at a time.
  - And never misses.
Rainbow 6 has the main characters using a two handed stance, but at one point their pilot hits the pistol range to blow off steam and uses a one handed side-on stance. It's realistically portrayed as being a lot less accurate, but he's older than the other shooters and apparently that's how he was trained back in the day.
Discussed in the Tom Clancy novel Teeth Of The Tiger, in which one of the protagonists expresses a preference for firing one-handed whilst standing side-on to the target, on the grounds that this presents a narrower profile and makes him harder to hit. Whether this makes up for the reduced accuracy (his preferred sidearm is a .45ACP weapon) is a matter for opinion.

Live Action TV

Blake's 7, justified most of the time by the fact they're using directed-energy weapons.
In Torchwood, Captain Jack Harkness teaches WPC Gwen Cooper to shoot this way rather than the modern two-handed technique, though it may just have been an excuse to feel her behind.
This was tested on MythBusters, and found to be reasonably accurate in comparison to the classic two-handed "Weaver" technique, and far more accurate than shooting from the hip or using Gangsta Style.

Tabletop Games

Most tabletop role-playing games featuring them consider pistols, revolvers, and possible futuristic equivalents thereof one-handed weapons as a matter of course. Two hands are for rifles, shotguns, and most automatic weapons.
GURPS assumes that characters fire all small arms one handed by default; using a second hand braces the gun, giving a small bonus to hit.
The World of Darkness games assume characters are firing pistols two-handed and has a higher Strength requirement for one-handed use.

Video Games

Fallout: 1 and 2 both had a trait that allowed you to use one-handed weapons better with an accuracy penalty to two-handed ones.
- Fallout 3 plays with it. By default, handguns are held one-handed and fired from the hip but using careful aiming (right mouse button in the PC version) makes the wielder hold the gun with both hands at eye-level as well as zooming in slightly. Also, the Gunslinger perk increases one-handed weapon accuracy.
The Spy's Revolver in Team Fortress 2. The Engineer also holds his pistol one-handed, but the Scout (who wields an identical pistol, albeit with less ammo in reserve) uses two.
- The Spy actually needs to fire one handed, otherwise he wouldn't be able to see how much charge his Invisibility watch has left or hold the Dead Ringer.
Ashelin from Jak and Daxter usually wields her handgun single-handedly, as does Veger.
In Boktai, both Django and Aaron fire their smaller Solar Guns one-handed during normal gameplay. During the cutscene where Aaron fires his first shot, he uses both hands; the resulting shot is so powerful that it goes through the skeleton he was firing at... wait, change that. The shot was big enough to annihilate the skeleton and keep on going!
Shepard in Mass Effect uses two hands in combat, but only one when s/he wants to look cool (like at a photo op) or is threatening someone.
Soldier of Fortune's Desert Eagle-lookalike Hand Cannon is fired one-handed.
In Half Life, Gordon Freeman holds his trusty low-powered, low-recoil Glock 17/Beretta M9 two-handed, but somehow fires the high-power, high recoil Colt Python revolver with one hand. In Half-Life 2 it's reversed, with the USP Match held one-handed and the Python held two-handed. It just goes to show that Revolvers Are Just Better.
Nero in Devil May Cry 4 fires a double-barrel revolver in which the caliber is almost that of a Smith & Wesson Model 500 revolver with one hand. Revolvers of that size are normally shot with TWO hands to brace for recoil. Can be justified by him being a quarter-demon with superhuman strength, much like Dante.
Saika Magoichi from Sengoku Basara fires her flintlock pistols one-handed at all times and has impeccable aim. Thankfully all her other guns she holds with two.
The first-person models for some pistols in Call of Duty: Modern Warfare 2 and 3 suggest that the player character holds and fires them in this manner, though this is not the case in third-person.

Web Original

Arguably common in Survival of the Fittest; while it's rarely, if ever, outright said how a character with a handgun is actually holding it, handlers tend to assume the character is doing this instead of the proper two handed grip unless the post says otherwise or if it's a handgun such as a Wildey pistol or Desert Eagle that would be completely absurd to fire off one handed. This is, however, justified with guns like revolvers or the aforementioned Beretta M1934, which were designed to be able to be used one handed.

Real Life

Many handgun shooting events require the shooter to use only one hand.
A common misconception is that the only "proper" method of firing a handgun is using two hands. However, professional use of one-handed firing is not unheard of, more so in the past than now. In fact, it used to be how many militaries trained their men to shoot since it developed from the shooting styles used for the earliest military pistols, which were designed to be fired one-handed.
- A professional is also trained to hold a handgun in one hand when his other hand is holding something else, such as a flashlight. One of the more famous holds on mainstream media is the Harries Hold.
Almost all single-actions revolvers are made to be fired with one hand and become very awkward when using the modern two handed setup. It also doesn't help that if that second hand isn't placed properly, you can lose fingers.
If someone was badly injured, silly or desperate, some muskets could be fired one handed, mainly because the accuracy of a musket was so poor anyway.
Generally, almost any handgun (up to and including hand cannons like the Desert Eagle) can be accurately fired one handed with proper training and practice, the hard part is holding the gun steady with your arm extended and not so much the recoil, that's why you see people in westerns using their off arm to support their shooting arm.

Longarms and Larger